Airship construction



/Q "'sept. .8, 1925. 1,5525808 v A.' F. sULzER AIRSHIP CONSTRUCTION Filed nec.' 7, 1921 51 INVENTOR ATTORNEY wlTNEss Patented Sept. 8,`y 1925.

UNITED STATES PATENT OFFICE.

ALBERT F. SULZER, OIF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK COMPANY, OF ROCHESTER, NEW YO'RK, A CORPORATION OF NEW YORK.

AIRSHIP CONSTRUCTION.

Application filed December 7, 1921. Serial No."520,764.

To all whom t may concern.'

Be it known that I, ALBERT F. SULZER, a citizen of the United States of America, residing at Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Airship Construction, of which the following is a full, clear, and exact specification.

This invention relates to airship construction. One object of the invention is to provide airship .members which include a protective coating that will retain its flexibility and' insolubility when exposed to moisture and the low temperatures which Will prevail at high altitudes. Further objects will hereinafter appear.

In the -accompanying drawing:

Fig.- 1 is a perspective view of part of an aeroplane wing, certain parts being broken away;

Fig. 2 is a fragmentary sectional view of an aeroplane wing embodying my invention;

l, Fig. 3 is ay fragmentary section of an aeroplane wing fabric coated in accordance with one form of my invention.

While my' invention is of general applicability to all airship parts which lit is desirable to protect' by a flexible and insoluble coating, it is particularly beneficial when embodied in the wings of aeroplanes. For this reason, the following illustrative .description will be chiefly devoted to that field. It is to be understood, however, that the underlying principle of my discovery may be applied to other .parts of aeroplanes and even to parts of airships of the lighter-thanair specles.

Aeroplane wings are usually constructed of a light framework over which is stretched a textile fabric. The latter is then coated with one or more layers of varnish or dope which tends to contract on drying and thus stretches the fabric tightly. At the same time the fabric is protected against moisture. The basis of these dopes has heretofore been chiefiy cellulose acetate. I have found, however, that at very low temperatures which are not infrequently met with at high altitudes, or in winter months, the cellulose acetate tends to become brittle. I

have discovered, however, that when cel-i lulose ethers, such as water-insoluble ethyl `stretched the fabric 2 bearing the coating of cellulose ether 3. Instead of the single coating indicated in Fig. 2 there may be a plurality of coatings, as indicated at 31 in Fig. 3. Y

By way of example, I may dissolve 10 parts by Weight of water-insoluble ethyl cellulose in 33 parts of denatured alcohol and 7 parts of benzol. Of course, any equivalent volatile solvent can be substituted. This is applied to the aeroplane wings in the same way that cellulose acetate dopes have been hitherto used. These being well known require no description here.

In addition to the ingredients given in the above example, I may add small amounts, say for example 1 or 2 parts, of high boiling substances or plasticizers like t-riphenyl phosphate, tricresyl phosphate, camphor, monochlorbenzol, etc. IVhen several layers are employed, as indicated in Fig. 3, the coating next the fabric may be;

cellulose ether varnish having little or` no high boilers or plasticizers. The upper layers may have much larger amounts of thesel substances.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

An aeroplane member comprising fabricv mounted on a frame and protected and held taut by a shrunk coating containing Waterinsoluble ethyl cellulose of the type which is highly resistant to becoming brittle at low temperatures, said coating comprising a layer directly on the fabric containing substantially no plastifiers, and having thereonsuccessive layers of cellulose ether containing substantial amounts ofa plasti- Iier.

Signed at Rochester, New York, this 29th day of Nov., 1921.

ALBERT F, Sm-ZEE. 

